|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Materials for High Temperature Applications: Next Generation Superalloys and Beyond
||Phase Evolution and Creep Properties of Nb-rich Nb-Si-Cr Eutectics
||Florian Gang, Alexander Kauffmann, Martin Heilmaier
|On-Site Speaker (Planned)
Nb-Si based alloys are promising novel materials for high temperature structural applications. Good mechanical strength and oxidation resistance can be achieved simultaneously by e.g. combining different phases in a very fine eutectic microstructure. Solely the ternary system Nb-Si-Cr exhibits a Nb-rich ternary eutectic. In this system, silicon is known to improve the creep properties by formation of silicides. Chromium is added to improve the oxidation resistance due to Cr2Nb Laves phase formation. However, the nominal compositions stated in literature are contradictory and report the presence of different phases. Therefore, the Nb-rich eutectic in the ternary system Nb-Si-Cr is determined experimentally. The phase evolution during solidification of different (near-)eutectic alloys is studied as well as the phase stability when employing heat treatments up to 1500 °C for several hundred hours. The resulting microstructures are comparatively assessed. Compressive creep test at 1200 °C give insights into acting creep deformation mechanisms.